Bone Abstracts

Objectives: We recently identified a heterozygous missense mutation c.652T→G (p. C218G) in WNT1 as the cause of severe primary osteoporosis (Laine et al. New Engl J Med 2013). The mutated WNT1 reduces activation of the canonical WNT1/β-catenin-signaling, resulting in decreased osteoblastic function. The mutation was originally identified in a large Finnish family presenting with dominantly inherited, early-onset osteoporosis, with affected...

Objectives: The skeleton and adipose tissue interact. Our aim was to evaluate the interactions between adipokines and bone metabolism, and their association with disease-related factors in patients with severe juvenile idiopathic arthritis (JIA).Methods: The study included 49 patients (median age 14.8 years, median disease duration 10.2 years) with refractory polyarticular JIA and 89 sex- and age-matched healthy controls. The subjects underwent clinical ...

Background: Osteogenesis imperfecta (OI) is a genetic disorder with low bone mass and bone fragility. Type VII OI is one of the autosomal recessive subtypes and clinically moderate to lethal. It is caused by mutations in the cartilage associated protein (CRTAP) gene. Currently <20 mutations are known.Case description: An 11-year-old Iraqi female was referred to our hospital after immigration to Finland. She had suffered numerous peripheral a...

Objective: Although obesity is a risk factor for vitamin D insufficiency, its impact on vitamin D-binding protein (DBP) concentration, and thereby possibly also on free 25OHD, is less well known. Our aim was to compare total and free serum 25OHD, and DBP concentrations between obese and normal-weight young adults at baseline, and their responses to cholecalciferol supplementation.Design: A 12 weeks’ randomized, double-blinded clinical trial.<p c...

Vitamin D and its metabolites are bound to vitamin D binding protein (DBP) in the circulation. Only a small proportion is in unbound, free form. According to the ‘free-hormone-hypothesis’ only the free form is biologically active. DBP is a polymorphic protein and different variants of the protein differ in their ability to bind vitamin D. This may have an impact on the amount of free and bioavailable (free+albumin-bound) 25-hydroxyvitamin D (25(OH)D) in the circulati...

Phosphorus intake in western countries is high due to abundant consumption of animal protein and also because of the expanding use of highly absorbable food additive phosphate (FAP) salts in food processing. P is essential for hydroxyapatite in bone, but short-term studies have shown that high P, especially FAP, intake has acute negative effects on bone metabolism. In this study, we investigated the associations between dietary P intake and bone turnover markers by using a cro...

The role of the WNT pathway in skeletal maintenance has been extensively studied since the identification of mutations in key signaling WNT mediators (LRP5 and sclerostin) in high and low bone mass phenotypes. However, the identity of the key WNT ligand that signals via LRP5/6 has remained unknown. We aimed to identify genes with a major effect on the skeleton by studying individuals and families with early-onset osteoporosis or osteogenesis imperfecta (OI).<p class="abste...